The present invention relates to a new and improved construction of a combustion chamber or compartment for a gas turbine, wherein within the combustion compartment casing or housing the air distribution chamber and combustion space or chamber are spatially separated from one another.
Gas turbines are increasingly subjected to the strict environmental regulations of many countries as concerns the composition of their exhaust gases. During the operation of gas turbines it is particularly difficult to comply with the regulations concerning the maximum permissible NO.sub.x --emissions. Thus, at the present time regulations are in force, particularly in the United States of America, wherein the content of NO.sub.x --emissions must not exceed 75 ppm at 15 percent by volume O.sub.2. Similar regulations must be observed in most of the industrial countries, and it is to be expected that in the future the permissible emission values or coefficients will be set lower, i.e. become stricter. These regulations, up to the present time, only could be complied with by resorting to the technique of injecting large quantities of water and steam into the combustion compartment or chamber. These auxiliary aids, in other words, water or steam, which were employed to reduce the emissivity, however, are associated with a number of decisive drawbacks.
If water is injected into the combustion chamber, then there must be expected an impairment of the combustion efficiency. Additionally, water is not always available or in adequate quantities, particularly in countries having low precipitation. Furthermore, prior to using the water it must be processed because many minerals, such as, for instance, sodium, cooking salt and so forth, which appear in water have a markedly corrosive action upon their surroundings. This processing of the water is expensive and associated with considerable consumption of energy.
On the other hand, if steam is infed to the combustion chamber, then there can be circumvented the above-discussed impairment of the efficiency of the combustion process. Yet, generating steam presupposes that water is available and the preparation of steam from water equally requires considerable energy expenditure.